2013年3月8日 星期五

School myopia in 80 years

This graduation photo of the Class of 1933, Tamsui Elementary School [courtesy of Mr N Hirokawa], shows that none of the students wore glasses. Vision screening with a visual acuity chart was already a standard, in fact, mandatory practice, at that time. It was tested in classrooms by class teachers. More recently, it is carried out by school nurses assisted by teachers.

The DOH reports that by 2006, 61.8% of the 6th Graders are myopic (near-sighted), and in seniors at high schools, 85.1%. This alarming trend continues even today.

While the intense schooling with increasing urbanization in Taiwan may be fundamentally responsible; however, the myopization factors still remain unknown. A large-scale study conducted by EyeDoc and his colleagues may have begun to provide some answers.

Below is an official announcement on the impending publication (photo of sunset in Tamsui coutesy of Christina Hong) by EyeDoc's group:

Risk Factors for Myopia in Taiwanese Children

Under 12

By age 11 almost 50% of
children in Taiwan are myopic
(at least -1D). Our authors studied
almost 2,000
elementary school children (ages 6 to 11 in grades 1 to
6) and found that, of the 20 myopization factors they
looked at, two thirds
(66%) of refractive error were
associated with just 4 of those myopization factors.
Those associated with decrease in myopic refractive
error were daily outdoor spectacle wear, spectacles for
different
working distances, and weekend outdoor
physical activities.

4 則留言:

I can remember when I started to wear eye glasses. It began maybe in the eighth grade. An English teacher (Taiwanese) one day asked me in class if I was near-sighted, since I was squinting my eyes looking at the blackboard. I don't remember what I replied, but I remember her asking me because this teacher must be the loveliest lady in the whole town. Naturally I tried to study English hard partly for the sake of getting her attention. But studying was not the reason how I became myopic. The culprit was the TV.

My father got us a TV set in the living room but forbade us to watch it after 10 p.m. or thereabout. But the good stuff, the Hollywood shows like Star Trek, Staski and Hutch, those came on after 10. So I had to sneak in to the living room after my parents went to sleep, turned all the lights out, sat less than a meter away from the muted tube, and watched the captioned shows one after another till the station(s) signed off. I had to sit right in front of the TV so that if there's any sign that my mother was coming out to the living room, I could turn the TV off first and pretend to be just sleeping there. A few months after the arrival of our TV, I began to have blurry vision.

One of my cousins talked to me that becoming near-sighted was bad for me. I agreed with him rationally. However, the fashion in those days was that he who wore eyeglasses had more 氣質 (class?). So my journey towards myopia continued. My poor eyes! How I suffered for that vanity now.

Very interesting story. Indeed, teachers and mothers are usually the first ones to notice children who squint to see (similar to looking through pinholes). Duration of TV watching and room illumination surprisingly are not among the major risk factors.

Some normal-sighted youth in Taiwan actually wear glasses with no prescription lenses just to look cool, so this part of the Taiwan culture has not changed.

Looks like I had jumped to a conclusion first and then subjectively picked some data to fit my theory, kind of like putting the cart before the horse.

I can't recall how I got into this habit of reasoning. But while it doesn't work in science, it does make story-telling interesting.

My cousin was very mildly myopic at one point when he was young. He said he did some eye-exercises (looking at distant landscape or green trees) and that corrected his vision. He told me to try it. That was long ago and my memory is questionable. But his vision was good enough to qualify him as one of the standing guards in some important place, like the Presidential Palace or Sun Yat-sen Memorial Hall, when he was doing his military service.

Potentially, there maybe an unlimited number of myopization factors. It is just that each one has a different weight. From our data, TV watching etc are relatively unimportant, statistically speaking. Individual mileage may differ, though. The same goes for myopia management. Your cousin's method has some support as 30-min breaks from near work appears to lessen myopia progression somewhat. By the age of military service, myopia progression would have stopped all by itself. I guess your cousin's refractive error was around -0.75D, a bit myopic but with squinting, he could pass as one with 20/20 vision.